Project Summary Abstract Posttraumatic Stress Disorder (PTSD) is highly prevalent in Veterans Affairs (VA) primary care patients (~11.5%) and is associated with significant functional impairment, compromised health, and economic costs. While effective psychotherapies for PTSD are available in VA specialty mental health care settings, primary care patients do not routinely engage in or complete these specialty services. Therefore, alternative delivery models are needed. This proposal integrates two lines of research: mindfulness training and peer support services to test a low-stigma intervention in primary care: Primary Care Based Mindfulness Training (PCBMT). Brief mindfulness training focuses on skill acquisition to help patients manage distress and can serve as a gateway to more intensive treatments for Veterans who are not yet willing to discuss their trauma histories. Peer support specialists help shift treatment away from the medical model focused on symptom reduction to a recovery model focused on leading a meaningful, purposeful life, with or without ongoing illness. This proposal aims to refine our existing PCBMT to be co-delivered by VA mental health providers and peers and then test important aspects of feasibility to prepare for a future full-scale pragmatic clinical trial. First, VA providers and peers will participate in PCBMT led by study investigators who are certified Mindfulness Based Stress Reduction (MBSR) instructors. Next, study staff will gather feedback from the trained providers and peers for further adaptation and implementation. After this, providers and peers interested in being trained as PCBMT interventionists will be trained by study investigators. Finally, a pilot RCT will be conducted. Both treatments conditions will consist of four, 90?minute group sessions co-facilitated by a VA provider and Veteran peer. The long-term goal of this research is to improve clinical and personal recovery outcomes for Veterans with PTSD. Our immediate goals are to refine PCBMT based on Veteran, provider, and peer feedback then test the methods needed to conduct a future full-scale RCT, in accordance with the following aims: 1. Gather VA mental health provider (n=5) and peer (n=5) feedback to refine PCBMT to a) ensure successful implementation in the VA setting (including creation of a provider manual and standardized provider/peer training curriculum) and b) maximize Veteran skill development to aid in future participation of evidence- based treatment for PTSD. 2. Assess the feasibility of conducting a pilot RCT (N=60) comparing PCBMT to a PTSD psychoeducation group on a) rates of recruitment and study retention, b) participant adherence and retention in treatment, provider and peer treatment fidelity, c) participant acceptability (satisfaction, perceived helpfulness) in PCBMT and control condition, and d) measuring outcomes of interest for the future larger trial including: PTSD severity, psychosocial functioning, recovery orientation, active engagement in mental health care.